1. Field of the Invention
The present invention relates to a chuck assembly for clamping a tool.
2. Description of the Related Art
As shown in FIG. 1, in a chuck assembly in accordance with, for example, Japanese Patent Application Laid-Open No. Hei 4-365504, a rotary sleeve 32 provided on a body 31 is rotated, jaws 34 engaged with rotary nuts 33 are moved back and forth to be opened and closed by the rotation of the rotary nuts 33 rotated together with the rotary sleeve 32 to thereby clamp the tool by the jaws 34, the rotary nuts 33 are formed into an annular shape with the divided nuts, and a shape holding ring 35 is provided around the rotary nuts 33 for holding an overall shape of the rotary nuts 33 composed of divided nuts attached to an inner circumferential surface of the rotary nuts 33. In this case, reference numeral 37 designates a grip sleeve.
By the way, if the shape holding ring 35 attached to the rotary sleeve 32 for holding the shape of the rotary nuts 33 is simply engaged with the rotary sleeve 32, there is a fear that the rotary sleeve 32 would fall apart therefrom. Accordingly, in the conventional chuck assembly, an annular groove is formed in the inner circumferential surface of the rotary sleeve 32, and a stop ring 36 is arranged for the annular groove to thereby prevent the rotary sleeve 32 from falling apart.
However, it is troublesome to arrange the stop ring 36. Also, it goes without saying that the cost for the assembly is increased corresponding the provision of the stop ring 36.